Revert 271459 "Remove stray platform_file.h from webkit"

trunk/src/webkit/browser/fileapi/quota/open_file_handle_context.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WEBKIT_BROWSER_FILEAPI_OPEN_FILE_HANDLE_CONTEXT_H_
 #define WEBKIT_BROWSER_FILEAPI_OPEN_FILE_HANDLE_CONTEXT_H_
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/platform_file.h"
 #include "url/gurl.h"
 #include "webkit/browser/webkit_storage_browser_export.h"
 #include "webkit/common/fileapi/file_system_types.h"
 
 namespace fileapi {
 
 class QuotaReservationBuffer;
 
 // This class represents a underlying file of a managed FileSystem file.
 // The instance keeps alive while at least one consumer keeps an open file
@@ skipping 28 matching lines @@
   scoped_refptr<QuotaReservationBuffer> reservation_buffer_;
 
   base::SequenceChecker sequence_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(OpenFileHandleContext);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_BROWSER_FILEAPI_OPEN_FILE_HANDLE_CONTEXT_H_